Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Hot-Wire Volumetric Flow Meter

IP.com Disclosure Number: IPCOM000120324D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Gattis, WM: AUTHOR [+3]

Abstract

Disclosed is a device which directly measures the volumetric flow rate, rather than the linear velocity, of a flowing gas. The device operates on the following two principles: 1) the electrical resistance of a metal wire changes with a change in temperature of the wire and 2) the rate of cooling of a heated wire in an air stream changes with a change in the velocity of the air impinging on the wire. These principles are the same as those on which a Hot-Wire Anemometer works.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 58% of the total text.

Hot-Wire Volumetric Flow Meter

      Disclosed is a device which directly measures the
volumetric flow rate, rather than the linear velocity, of a flowing
gas.  The device operates on the following two principles: 1) the
electrical resistance of a metal wire changes with a change in
temperature of the wire and 2) the rate of cooling of a heated wire
in an air stream changes with a change in the velocity of the air
impinging on the wire.  These principles are the same as those on
which a Hot-Wire Anemometer works.

      The Flow Meter consists of a wire screen, a constant-current
power source, and a volt meter.  The screen is made from insulated
wire which has a high change in electrical resistivity with change in
temperature.  One embodiment of the invention could be a square
screen, made from insulated platinum wire, with wires uniformly
spaced in both directions (see Fig. 1).  The wire is arranged in a
serpentine fashion, so that the screen is made from one continuous
piece of wire (see Fig. 2).

      The screen is connected across the power supply so that current
flows through the wire.  Electrical energy is dissipated in the form
of heat due to the resistance of the wire, causing the wire to heat
up.  The temperature of the wire will rise to a value where the heat
carried away in convection (either free or forced convection) equals
the power input from the power supply.  As the wire heats up, its
resistance changes, until a steady state is reached....